Players · H · Pitcher · 2026 regular season

Seth Halvorsen

Age: 26
B/T: R/R
Height: 6' 2"
Weight: 243 lb
Number: #56

Born: February 18, 2000 in Chicago, IL, United States
MLB debut: August 30, 2024
Drafted: 2018, round 30
College: Tennessee
High school: Heritage Christian

Compare with…vs Drew Pomeranz vs Justin Topa vs Chris Roycroft

dbWAR: -.5
IP: 29.0
ERA: 5.90
FIP: 6.17
K/9: 7.1
FIP−: 148

Seth Halvorsen is a relief pitcher for the Colorado Rockies. In 2026 he struck out 23 batters over 29.0 innings across 32 appearances, going 1-2. His ERA of 5.90 was 41.0% higher than the league average of 4.18 — 15th of 21 on his team, and 480th of 539 among MLB pitchers with 20+ innings. Stripping out defence, his 6.17 FIP suggests the ERA was no fluke. He missed bats on 21.0% of swings (10.2% of every pitch he threw), walked 12.1% of the batters he faced and struck out 16.3%. His -0.5 dbWAR is built from that FIP rather than runs allowed, so it credits him for what he controls and not for the defence behind him.

League context

Percentile among qualified pitchers, 2026 regular season.

FIP6.17

K/97.1

WHIP1.72

WAR-.5

WAR by season

Pitching Regular season

Standard and advanced, by season. Regular-season games only.


2026	COL/LAD	32	29.0	1	2	0	33	19	23	17	5.90	6.17	1.72	7.1	5.3	141	148	-0.5
2025	COL	42	39.2	1	2	11	41	22	36	21	4.99	5.20	1.56	8.2	4.8	120	125	-0.1
2024	COL	12	12.1	2	1	2	8	2	13	2	1.46	3.90	0.81	9.5	1.5	36	96	0.1

Platoon splits

How left- and right-handed hitters fare against him.

Season

Opponent batting by the side the hitter bats from, 2026. Counted from play-by-play, so totals can differ from the box-score season line by a plate appearance or two.
Split	PA	AB	H	HR	BB	SO	AVG	OBP	SLG	wOBA	K%
vs LHB	58	47	17	2	9	8	.362	.483	.553	.449	13.8%
vs RHB	83	75	16	4	8	15	.213	.289	.440	.318	18.1%

Pitch sequencing

What Seth Halvorsen throws in each count, and what he follows each pitch with. Select any cell for the breakdown.

ShowBatter

Four-seamSliderSplitterSinker

Select a count to see exactly what Seth Halvorsen throws in it.

Pitch arsenal

What he throws, how hard, how often it misses, and what hitters do with it.

Season


Four-Seam Fastball	60.0%	313	98.9	2,310	40.3%	11.8%	68	.324	.999
Slider	28.9%	151	86.6	2,634	43.0%	38.7%	36	.139	.427
Splitter	9.2%	48	89.5	1,602	45.8%	25.0%	15	.333	1.145
Sinker	1.9%	10	98.0	2,118	30.0%	0.0%	3	—	—

Seth Halvorsen's arsenal by usage. Velocity is average release speed in mph, spin in rpm, and whiff rate is misses per swing — the cleanest single measure of whether a pitch beats hitters. BAA and OPS are what hitters did against each pitch, credited to the one that ended the plate appearance, and are left blank under 15 at-bats.

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Similar players

Nearest 2026 seasons by command, run prevention and role, on rate statistics rather than totals.

Matt GageSF

ERA: 5.60
FIP: 6.32
SO: 22
WAR: -0.5

Very close

Drew PomeranzLAA

ERA: 5.59
FIP: 6.93
SO: 17
WAR: -0.8

Ron MarinaccioSD

ERA: 6.09
FIP: 5.69
SO: 48
WAR: -0.7

Alex LangeKC

ERA: 6.75
FIP: 5.87
SO: 60
WAR: -0.7

How these are computed

wOBA uses linear weights measured from this season's own play-by-play rather than published constants, and wRC+ is park-adjusted against that same league. dbWAR is our own open implementation — not fWAR or bWAR — and the full derivation, including its simplifications, is on the methodology page.